A uniflow scavenging two-cycle engine used as an engine in a ship is provided with an exhaust port on one end side and a scavenging port on the other end side of a cylinder. When active gas is suctioned from the scavenging port to a combustion chamber in an intake stroke, exhaust gas produced in combustion behavior is pushed and is exhausted from the exhaust port with the suctioned active gas.
For example, Patent Document 1 discloses a scavenging port inclined with respect to a radial direction of a cylinder. Since scavenging gas flowing into the cylinder from the scavenging port flows with swirl, the scavenging gas is easy to maintain a separation state from an exhaust gas layer in the cylinder, and scavenging efficiency is improved. In addition, Patent Document 2 discloses a configuration in which a scavenging port is a so-called skewed port. Here, the skewed port is a port having a portion on an exhaust port side that is inclined with respect to a radial direction of the cylinder and a portion on a side opposite to the exhaust port that is parallel to the radial direction of the cylinder. The scavenging port is the skewed port, and thereby leveling of a scavenging speed is achieved when the scavenging gas flow toward a combustion chamber.